There's a parallel thread running in the new Panda section, here, which you may find interesting. Most folks are reporting a reduction in both power and fuel economy when running on E10.
Quite a few of us are switching to super unleaded; some of the brands in some parts of the country are actually ethanol free, despite being labelled E5.
Ethanol is generally bad for cars, though some may say better for the planet.
I tried the ethanol in the the Younger Mrs S.'s Rasputin (2013 1.2) and first impression was "no difference". It "might" have been a bit less pokey than before.. but that might have been paranoia.
Mind you.. I'm also now tempted to stick Super U/L in it..